Riveting machine



FIG. 1 is a front elevational view of a riveting machine, showing our new design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a side elevational view taken from the left of FIG. 1;

FIG. 4 is a side elevational view taken from the right of FIG. 1;

FIG. 5 is a top plan view thereof; and

FIG. 6 is a bottom plan view thereof. 

The ornamental design for a riveting machine, as shown and described. 